A traffic storm occurs when packets flood a network, creating excessive traffic and degrading network performance. Traffic storm control (also known as traffic suppression) monitors traffic levels over a predetermined interval, such as one second. During the predetermined interval, the traffic level is compared with a traffic storm control level, and if the traffic storm control level is exceeded, traffic is dropped for the remainder of the interval.
In accordance with an example embodiment, a system for communicating data packets includes an ingress interface and an egress interface. A storm controller coupled to the interfaces determine whether to forward received packets. Packets are forwarded while the rate exceeds a first threshold and is less than a second threshold while a predefined condition exits. The storm controller further limits traffic for the traffic flow to the first threshold while the rate exceeds the first threshold and the predefined condition does not exist. The storm controller further maintains data representative of credits available for each of a plurality of the traffic flows. Packets corresponding to traffic flow are forwarded while the associated traffic flow has credits available. Credits are added or subtracted in accordance with the thresholds.
In accordance with another example embodiment, packet communication method includes obtaining receiving data representative of a steady state rate threshold. Data representative of a maximum rate threshold is received. A traffic rate for a traffic flow over a time period is determined. A first packet for the traffic flow is received. Data corresponding to credits available for the traffic flow are stored. Credits are added or subtracted in accordance with traffic flow relative to the thresholds. The first packet for the traffic flow is forwarded responsive to the traffic rate for the traffic flow and available credits. A second packet for the traffic flow is received and dropped in accordance with the traffic rate for the traffic flow and available credits.